Time announcing system



June 11,1935. QAG. MILLER ETKAL 2,004,248

TIME ANNOUNCING sYAsTFM` Filed Dec. 22I 193s Ilosheets-shfaet 1 MNM.

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'Junll' 1935# `c. G. MILLR TAL 2,004,2487

" TIME ANNONGING SYSTEM Y Filed Dec. `22, 1955." `10 sheets-Sheet 1o Patented June 116, 1935 UNITED ,sfr-Ares i Charles-Gideon Miller, Montclair, and Allen liu-tV doit Bonorden, Fanwood, N. `.7.,assgnors to 'American Telephone and TelegraphCompany, acorporationof New York Y, i f

s This'inventionrelates to telephone exchange systems, and more particularly sto, systems in which a subscriber by4 calling `a. particular `line designation eitherby dialing as in machine 5 switching systems, or bythe aidv of an operatnr as granted to G. K. Thompson on February 22, 1927,

in manual systemsnmaylobtip connection with `a central time announcementbureau from which,

-at specied intervalsfannouncements are xvrrisltdel transmits `autonnttically`to the subscribers` line` the hour and minuteof the^ time koif day.` `I

"Ihe invention described `herein also embodies a `time announcing mechanism ,utilizing` photographic sound producing means Ionwhich purfpose the `call announcer mechanismidisclosed in s u Patent No. 1,645,573, granted to I-I.A M. BascomA on October 18, 1927 is adapted to thisinvention.

One time announcing system, to` which `further reference will be made, is described in PatentNo.

1,863,137- granted to C.; W. Keckler et` al, on `June 14, 1932, and in coissued Patents No. 1,862,519,

1,863,139 and 1,863,141 granted to R. F. VMasson-` neau,W. B. Prince and H.G. W. Brown, respecspeech by any'telephone subscriberwho may Vbe t tively, June 14,1932. ,This system embodiesal comprehensive distributing network mitrunlcs for n `serving aLplurality of centralomces in a metro-1 politan area Vfromafcentralitime bureau where time announcements are made orally by an operato!"` at periodic intervals.` s s i 1 p Y,

It is `one, ,of Vthewiiblects of `this.` invention toreplace such operator by means ofa,clo clt`con` trolled machine so that at periodic intervals the machine "is causedto announce the correcttime, such announcement being heard in the form of s connectedtothe'network of time announcement trunks Vfor `thefpurpose of obtaining the correct Y time.

"A further object is to insure a high degree of accuracy and continuity of `service for which pur-` pose.` two `machines and associated` clock-operated controlsare contemplated, each` acting asv check on theother; Either machine may fur-` nish the service and in the eventof certain types of failurethe service will be automatically taken overby the second machine.` s j Other and further` objectslofthe invention will be apparent fromthe' following description when p consider-eatin?connection withthe accompanying t drawingsdesignated Fig. 1 to Fig. 10,inclu`sive, which when arrangedin theorder shownin Fig. i fll illustrate a circuit diagram of' a system embodem thiSnvhiiOn-l Gener description j Referringtc 'the drawings, Fig. 1 shows at `|05 la groupof l5 pairs of counting relays, the proi, lglfssive operationfandrelease of `whichliscon-i trolled by"isochronous` electrical pulses obtained i Ironiaclockpendulum. Forthe purposeo! illus'-, tration, it assumedr that theperlod of'` the clock` pendulum is one second; hence,"two#electrical, i

pulses :per ,second may' be` obtained. i nlsource,

period maybe used,"it only being necessary that the period'be a `subrnultiple of the interval clansing between successive `pronouncements of- `the i gtime. The arrangement `is such that onceeach "second, Vone `ofthe 15 pairs of relays operates: -At

'theend or one-quarter ofa'minute the 15th-pair operates after which the cycle of count is*re of isochronous l` electrical pulses -otany .other` peated." produces a single pulse controlling i 1 'the quarter-minute group of counting ,s relays shown` as relay group 200=on Fig. 2. Four such quarter-minute pulses are, counted by this group Vwlriich thereupon originates one pulse to control r the`10 pairs of counting relayswhich constitute the minutegroupf shown as relay group'lll.

When this groupfofrelays has counted 10 oneminute pulses, it originates a single pulseinto` the 10s-minute counting relay group indicated as relay group 230." When sir:` l0-minute pulses, have been counted by the six pairsof counting Vrelaysin this group, 'indicating Athe duration of fininute's or one hour, this group originates a pulse Vtoadvance thev hour group of counting relays designated as relay group'300 on Fig; 3. j setting of `the quarter-minute; one-minute, 10- minute andhour countingrelay groups controls the setting of the associated quarter-minute, onep minute,- 10-minute and hour selection relays shown,.respectively, at 500 in Fig. 5, 400 in Fig. 4,

5H) inFigQ5, and`600in Fig.` 6. "Ihe selection relays control the orderiand selection ofthe filmt records from which is generated the speech makf ing up the complete time pronouncement;

Figs. 8 and 9. Thismachine takes the form of the call announcer machine `which is described in the 'aforementioned Patent No. 1,645,573, granted to H. M. Bascom. Referring toFigs. Band 9,

l2 film drums; Y and associatedparts will sumce for alldrunis on Y Y to The time pronouncing machine is shown on@l 55 motor drives two shafts, 853 and 854, through; `thenecessary reduction gears in gear bri-)X151V `On shaft 854 are 13 nlm drumsfand on shaft853,1 A description offene such drum" these shafts. A wide flanged wheel 9| 4 has on an extension of its ange a strip'of photographic film 92|, on which are recorded in the form of striations or otherwise, three records of the oral sound of the word eleven, equally spaced about the periphery. Outside of the circumference of the lm is located the stationary source of illumination 924, whose light when concentrated by the proper optical system indicated as 923, falls on photoelectric cell 922 after passing through the interposed lm. Associated withthe photoelectric cell is anampliiier 925, and speech cut-in relay 952. The operation of this relay during the period that one of the three records is passing the light source will connect the output of the amplifier to the common repeater 812 ,(Fig, 8).

f As previously stated, there are 12 film drums on shaft 853, each film drum bearing'three oral records of the .same word, but each film drum containing oral records of a different word; these are the oral sounds represented by the numerals one to twelve, inclusive. Similarly mounted on shaft 854 are 13 film drums containing oral records ofthe words oh, clock, and and",

halffi quarter, "thir- (theifrst syllable in the numeral thirteen), f- (the first syllable in the numeral fifteen),vteen (the last syllable in the numerals thirteen, ,fourteen, fifteen, etc.), and the numerals twenty, thirty,

A third shaft 851 carries a '26th nlm drum :866, with associated light source photoelectric cell,

of a revolution each half second, and the large.

drumone revolution each three seconds. vlit is convenient, although-not necessary, that one revolution of the large drum correspond to a multiple of a single pronouncement cycle of the small drum. Use is made of cams 86| and 858 on shafts 851 and 853, respectively, to effect the operation and release of the speech cut-in relays at the silent point in the revolution of the respective lm drums.

By the proper selection of film drums andthe progressive operation and release of their associated speech cut-in relays a complete pronouncement can be generated such as when you hear the tone signal it will be exactly twelve oh clock priorto the precise instant of time to Vwhich the pronouncement refers. A tone signal isy then generated at precisely 12:00 oclock. Subsequent time pronouncements follow one another at 15 second intervals. These are as follows, each being preceded by the introductory phrase:

"Twelveoh and one quarter Twelve oh and one half fTwelve oh and three quarters Twelve oh one Twelve oh one and one quarter and so on.

The hour and minute announcements from 12:10 to l2:19% take the form Twelve ten Twelve eleven, Twelve twelve Twelve thirteen. Twelve fourteen second pulses.

and those from 12:20 take the form lTwelve twenty Twelve twenty one Twelve twenty two, etc.

These are, of course, followed when necessary by the'proper quarter minute announcement and are preceded by the introductory phrase.

Fig. 10 shows the principal elements in a distributing system such as that disclosed in the aforementioned Patent No. 1,863,137, whereby the subscribers call may be terminated at the output of repeater 812 (Fig.8) over conductors 826 and 821. In Fig. 10 the telephone set of a calling subscriber is shown at |00|. The subscriber having dialed the proper number is' connected, through the medium of a line finder and district circuit |002 to a time announcement trunk circuit |003 common to the subscribers central oflic'e. Trunk circuit |003 is connected byinteroiice conductors V8211i and 821 to oneside of repeating coil 824. The

other and similar repeating coils, is connected to the output of repeater'812 of the particular time pronouncement machine giving the tlmefservice. Operation A description of the detailed method of operation will now be given? When locking key |54 '(Fig. 1) is operated in the direction shown, ground is connectedto pendulum |20 which, as stated before, has a period of one second. Twice each second it closes a suitable contact, such as a mercury cup |21. On the iirst contact, following the operation of key |54, relay |22a operates overa circuit from battery at key |52, left winding of relay |221), winding of relay |22a, the left normal contact of relay l22b, through the aforementioned mercury cup and pendulum to ground-at key |54. Relay |22a, operating, connects-groundv through its front contact, through resistance |23 and right winding of relay |221) in parallel. The ground supplied by thev pendulum acts to shortcircuit resistance |23 and the right winding of relay |221). Relay |221) is marginal and does not operate under this condition' When the pendulum contact breaks, its short-circulting effect is removed from the right winding of relay |2217,"

thus permitting it to operate'. When the pendulum contact makes the second time in each second, ground is connected to the left make contact of relay |221), short-circuiting relay |22aV and the right winding of relay |221). Under this condition relay |221:l remains operated but relay |22a releases. When the pendulum ground is opened, relay |221) also releases. Itis apparentV that once each second relay |221) is operated for approximately one-half second. This relay may, therefore,'be considered as the source of one-per- One secoud'countin'g relay gouplll When relay |2219 operates during the first second, a path is closed for operating the rst pair of counting relays. Ground at the right middle make contact of relay |221), over a control lead extending through the left outer normal contact of relay ||5b, the left normal contaets'vof relays H411, H31), H217, |||b, and H012, the rightnormal contacts of intervening b relays and right normal contact of relay |0|b, to a point common to the windings of relays I0 la and |0|b, through the windingof relay |0|a to battery on lead |53. Relay |0|a operates, extending ground from 'the left break contact of relay |0211, throughits owri rightmake contact, through the `winding of relay I VIf it is desired' to set the counting relays for |Ib `te `the` aforementioned 1 common point. Relayllb does not operate s'inceitfis short;` circuited I by the ground at relayjf I22b." When relay |22b releases, removing theshort" clrcuit, relay 110th thereupon operates, (transferring the controljlead from itsright back contact through its frontcontactto the succeeding pairof, relays,`

viz'., relays r|0211 and |02b, e On thesecondoperlation" ot relay o I2 2b, `refzl'ay I02a is' caused to yoperate"over` the: previously traced pathwhich now includes the `right'front` contact of relay I0Ib.;4 Relay r`I02a prepares a locking` path which includes the winding of relay l of operations continues; once each second the suc-` ceeding pair of` counting relays is caused to operate,` advancing` the control` lead to` the next pair Abeyond and openingthe holding path of the pr'eceding operated pair which thereupon' releasesg.

This 'progression continues through to the'15th pair of counting relays. I When'countingfrelay pair II5.isoperatedlthecontrol lead is extended directly [to the `windings of relay I0'Ia, and relay IIS. Following. the 31st contact of the pendulum, relayk I22bfis," again operated, operating relay IOI,` lthusg starting another Acycle vof progress through tl'ievl5 pairs of counting relays, In thiscase, relay] I6 als'oyoper-` ,lates over apathtvhich includesthe left outermake `contact .of relayl lib. o On the release" o'lf relay |2219, relayI I b1 operates and relay II Iiy releases.

Relay mlb, `operated,(opens theiiocking 'path of y relay pairI l which thereupon releases;

i During the approximate halt-.second "period thatrelay II Bois operated, `among other functions to be explained later, it connects ground through its right outer `make contact to lead `I I9,v Thus, `once every 15 seconds lead Y'I I9 is grounded for approximatelyone-half second. This ffonelperquarter` ,minutef, pulse `is vused to `advance `progressively the fou'pairs of counting relays in the quarter- "`1`Inlitialsettnglof `time countijffrelay-s"n.l o `Follo'ane the operation of locking-key] is .A necessary to operateone'pair of counting; relays in` they quarter-mind'tev group `2110fone-rninute sgroup" 210, lll-minutelglroup 230, andhour group` 300.` (Fig. 3). Assuming key |54 is operated precisely` at `112451@ then l; the next pronouncement of the associated relay pairs 3| I, 234, 2I5`andl202,

`respectivelyover individual obviouscircuit paths.` These relay pairs remainlocked throughthe right make contact of the-fa relayand theleft normal [contactof the .b relayin the` succeeding pair. "o ,Their operation is indicated by the lighting of the respectivelamps `3| I c, 2342I5 and 202e. These Mlalnpshmay be designated.."1l.,`` 4",. 5" and A1/2" e thus indicating visually the. liefto'be announced" lpriorto the next timesignal, j

minute countingy relay'group "2001 @circuit 'paths will then` be closed; 3

l2 oclocl, non-locking key `IliI alone may be oper#- ated momentarily instead ofl the iindividual non- ASSurning-thatvrelaypair 202 ivasoperated in the manner statedrthen `when lead I I9is next `grounded* in the' manner :previously described; a

path tobattery 'on lead-A I 60-is` completed through `the right outer normal contact of` relayl 204b,-right` normal Contact "of relay 20317,: right-make contact offrelay` 202b"and winding -ofL relayv 20311 which. operates. E Relay 20311; "operated, flights the` as;- Y sociatedlamp203c (provided locking.key|50,ise' i operated)M and preparesV thefiusual locking path` e 203|)- operates when the `ground is removed from lead I I 0.'l When relay `20317 `operatesjit, opens `the locking patlrof f'countinglrelaypair 2Il2at11its` left normal contact, grounds lead 203e,.and advances ithe extension "of lead-1| I9 to counting: relay pair 204.Y Countingrelay pairv 202releases`.` RelayV `202m, released, also opens the locking path and Iextinguishes lampi 202e. Relay 20212, released, removes ground fromlead 202e, restores `ground leased. I The completion ofthe next pulse onlead i I I 9 leaves counting: relaypair l20 I I operated whichl inturn releases pair 204; In ythis manner count- `ing-"relay pairs"'|fto` 204 `are each operated and `tact of relay 20413,isgroundedgatithe right outer make contact of yrelay 204a. Thisioneper,l

minute. pulsef'causes a similar progressiveopera- :tion and lrelease in numerical sequenceofthe `10` pairs of counting'relays in theminute relay group [when lead *l lsf is` momentarily groundedfie seconds latenfcounting relay pair` 2041s caused to operatein a similar manner and pair 203 is re` to right armature lof relay 20Ia and closes the p break in the control path through its rightnormal;

1 Counting relaypair 22|),` operatinglonce each \10 'release inniimerical sequence-fof the six pairs of e `"coi'inting relays inthe liminute relay group-230.`

Similarly, counting Arelay pair 236", operating once each minutes, originatesa .one-per-hour pulse by grounding'lea'd 23T-fior approximately period to cause afprogressive operation and' release A:inY numerical` sequence of the V12` pairs .of counting relays in the hour relay group 30|).` e

one 4half'secdnd atwthe beginning.; of eachhour o groups2llll,` 2I0, 230 and 300 causes the'operaminute'4 and hour` selection relay groups 500, 400, `5I0 and 60|),` respectively; Assuming'themext time signal will occurat 11:453/1',i counting relayf fbygroundingfileadf22| @for approximatelyonen l Y halfsecondat the beginning of reachijjlO minute` vperiod which causes la progressive` operation and relay 938 to control the record .,clock` Ground at vleft make contact'of relay 3| Ib, lead 3lle, normal contact ofImulti-contact transfer relay 3|4, winding of selection relay 6I I, common lead 128, winding of marginal relay 129 to battery. Groundat left make contact of relay 234D, lead 234e, a normal Acontact of relay 3| 4, -winding of selection relay 5|4, commonlead 124, vwinding of marginal'relay 125 to battery. Ground at left make contact Aof relay 2I5b, lead 2|5e, a normal contact of relay 3|4, winding of selection relay 405, common lead .133, windings ofgsensitivere lay 134 and marginal relay 136 to battery. Ground atleft make contact of relay 203D, lead 203e, a normal contact of relay .3 I4, winding of selection relay 503,V common lead 12|, winding of marginal relay'122 to battery.

Selection relays 6H, 5| 4, 405 and 503 operate under this condition, but theassociated series marginal relays 129, 125, 13B and 122 do not. Should two or `more selection relays in the same group be energized because of trouble conditions, the associated marginal relay Will operate and block the pronouncement in the manner to be shown later.

Selection relay 6| I operated connects lead 142e,

which is common to all selection relays in the 600 group, through its left make contact to lead 9| I. Similarly, selection relay 5|4 connects common lead 143c to lead 940. erated, closes a path from common lead 144e, left `outer normal contact of relay 5| I, lead 4|5, left inner make contact ofrelay 405 to lead 905.

- Selection relay 503 at its left inner make Contact connectsicommon lead 14150 to lead 903 and at its left outer `make contact connects common lead 141e to lead 900qs. Lead 145e remains connected to lead 850e through the left outer normal contact of relay 504.

Leads SI I, 940, 905, 850e, 903, 900qs terminate,-

respectively, at the windings of speech cut--in relays 952, 936, 045, 814, 943 and 929 which will if operated connect respectively, the output of the -film records eleven, forty, ve, and,

three, and quarters to the input of repeater 812. It yonly remains necessary to ground each of Vleads142c, 143C, 1440,-145c, 146e, and 141e for the proper interval of time and in the sequence enumerated to obtain the announcementv eleven forty-five and three quarters. The manner in'which this is accomplished is described under thek sectionV entitled Announcement of time". Y

Certain lrn records are selected by a combination of Aoperated selection yrelays instead of by a single relay. Once each hour, from 59'45 to 59'60 pastthe hour, lead 144cis connected to The circuit path is lead 144e, left middle normal contact of relay'5l I, lead 4|6, left inner make contact of relays-4|0, 5,04 and 5I6, lead 900e to relay Yiii-2 respectively.l Similarly leadv4|6 is comj mon to relays 404 and 406 to 409 inclusive to control respectively the4 output of lm records four, and six to nine inclusive.

From 12'45" to 19'45" past the hour the llm Selection relay 405, op-

Announcement of time Precisely 11V seconds before the time signal is transmitted, i. e., when counting relay |05a is operated, a checkis made (of certain functions preparatory to the pronouncement. Ground at Vthe left make contact of relay |05a, lead |62, left middle normal contact of transfer' relay |68, winding of relay 15| ofrbattery. Relay 15| operates connecting battery to lead 149 which is common tothe right windings of checkl relays 152 to 158, inclusive. vThese relays operate connecting ground through their left or high-resistance winding to leads 14|c to141c, respectively. Y Y

When counting relay pair |05 releases one and one-half second later, relay 15| also releases re- Y moving battery from the right windings of relay 152 to 158,V inclusive. Relays 153 to 158 remain locked because leads 142e to 141e, inclusive, as was shown, were connected by the operated selection relays to the windings of the respective speech cut-in relays, 952, 936, 945, 814, 943 and 929. Relay 152 also remains locked up because.'

lead 14|c' terminates at the winding of speech cut-in Vrelay 31|. `The left windings of relays 152 to 158 are sufficiently high in resistance as to prevent the associated series connected speech cut-ink relays, and relay 832 which are marginal, from operating. The purpose of relays 152Y to 158, inclusive, is to check the'continuity of the paths required Vto operate the speech cut-in relays. In the event any path is open the corresponding vrelay in the 150 group will not remain locked up and it will., therefore, prevent the subsequent 'closure of a chain circuit, to be next described.

Following the release of relay 15| a chain circuit is completed; battery through the left winding of relay 803, normal contacts of relays 136,

129, 125, 122, 15|, 14|b, 1422), make contacts of relays 152, 153, normal contacts ofrrelays 143b andl 1441:, make contacts of relays 154 and 155, normal contacts of relays 14517 and 1461, make contacts of relays 156 and 151, normal contacts of relays 1411), and 148D, make contact'ofV relay 158, left outer normal contact of relay 802 to ground. If this chain circuit is continuous it is an indication that the equipment is prepared to make a `complete pronouncement,rv The effect of an open chain circuit will be discussed later.

Relay 803, in the aforementioned chain circuit, operatesland connects ground from the right normal contact of relay 802 through its own left make contact and outer left make contactof relay t! 0, winding of relay 825 to battery, operating relay 825. This relay on operatingV reverses the battery and vground with respect to leads 826 and'321 which connect with the aforementioned network of time announcement trunks the essential partsof which are shown in Fig. l0. This reversal may bevused to control certain relays (not shown) in all trunks, such as |003, to Veffect `a cut through condition for the purpose of enabling the subscriber'tohear the pronounce'- fshafte'ss; anden is `sten that leads staand windlng'funtil relay r|08a release`s.`

vCam 86| grounds leads 882 and n l n 2,004,241; mentl of fthe time'f Calls connected Ato ytime `l`"announcement `tri'inks subsequent to'ythe `operation ofrelay 825 would not'be out through until 15 seconds laterwhen the seriesofy events now-bef ingjdescribed isrepeated. 1

the pronouncement relaygroup '140. This procedureis initiated when countingielay |08a op# crates.V Ground at leftfmake contactof relay |08`q, llead |68left inner normal contact offrelay |68, YleadXlH, rightmake contact of relay "'808 to battery through the rightwindings of relays 80,3` and 802 in parallel.` ',Relay 802` operates, openingat its left normal contact, the chain 'cir-"` cuit which includes the leftwinding of Yrelay 803 which, however, is held operated through its `right In, the]A event,the previousl` describedchain circuit was open, relay 803 would not have been operated in which event the ground from the left make contact of relay luawfmld beam,

tended through the right normal contact of relay 803, rightwinding of relay 8| 3 to battery. `{Relay 8|3 would, therefore, operate and^eifect`a transfer of the service to theother machinefin themanner to be described later.

Assuming, however, the chain circuit was properlyclosed thenwhen relay .802 operates,

it `1o`cksthrough its left winding `to ground at r'elayll8lll.` Relay' 802 operatedalsof opensthe i operating` pathof `all relays `82,5 which `release restoring battery and ground to leads 826`and' 821, respectively,`of all trunks. This may set up a condition on allcallsy previouslycut through to theltime announcement system whlchwill cause a charge to bexnade` when the calling'subscrib-` ers subsequently disconnect." `Iitelayln, operated, also yprepares a circuit for starting -the announcement with the "aid ,of cams 86| and 858V f nettimenun` whose relation with each other drumswillnowfbe described.

speech record haspassed the light-beamfcam A858 removes the" ground from 'lead 1859 and. Agrounds momentarily lead 860`for the purpose of y checking the` output of the record in 'the manner4 to be described later.'` The relation between 862 are grounded' simultaneouslybut ,that the groundon lead 1859 'lsremoved before that` on` lead 862,;` H g V- i Following thejoperationof relay 802 the subsequent closure of the contacts at cam 86| .starts the pronouncement.` Ground at cam` 86|over lead 862, outer left normalcontact of relay 14212,` right make` contacto! relay 802, left normalvconf tactof relay v1Mb, winding dfgrelay `14|a,flead 809 left normalcontactof `relay`801 to battery*I i Relay 14|a.` operates and prepares, through its left inner make contact, the usual locking" circuit path whichincludes lthe'winding of the associat- "ed ibf' may. YRelay mb 1 operates when thel ground `on` lead 862 `is` removed by `the` further l rotation of cam 86|.V Relay 14|a," operating, also closes the following circuit path tooperate speech Eight seconds before the time signal, the-start circuit is closed"f to' effect lthe pronouncement by progressively operating` the pairsv of relays in cut-in` relay 81 I ground through the right nor-4 mal' contact of relay 808, right make contact of,

relay 14,|aright normal contact `of, relay "2a," lead 14|c, windingbi!A relay 81|, commomlead SIB, winding of marginal;` relay y832 to battery. 1Relay 81| operatesf-andirelay 162which`isa1so connected to lead 14|c,.,is shortfclrcuited and,`

therefore, releases, opening its, holding circuit.

`Marginal relay 882 does `not operate. It `will be seen'thatrelay 81| is caused tonleratejustbe-` fore the beginning `of the `introductory,speech recorded on film drum 866. During its revolu-` tion the record visA electrically "transmitted through the mediumigof, -the photoelectric cell `868 and amplier 810,;over leads 863 and`186l,

repeater 812, make contacts of relaylfll|8Aandv left windings of all repeating coils such as repeating coil 824.1 Here itis transformed, throughfthe right windings of each repeating coilfthencevover interonice trunk conductors such as 826 and 821 of the aforementioned trunk network to` all sub1 scriber lines previouslygcut through uto vthis sys` i ternL and thereby reproducedtas speechH Vin the telephone `receivers at thegsubscriher stations. l

At the completion of" `one revolution of ,`865,cam 86|-again groundsgleadsv |46 andf862.

`Grround on lead 862 over lthe previously described.`

path to the lefty armature of relay 14|bno'w con- `tinues through fthe make contactfvof this relay,

left normal contactJ of relay 1421),.wincli`ng'` `of `relay ma lead .aoareontaecpf relay' su tu; hat tery. Relay `|42aoperia.tes preparing a locking Vcircuit at its, left make contact which includes the winding of relay 14217.4 When theground on. lead, 862 is again removed relayjg142b oper-` ates.,` When relay 142e operates theground pre,-

fromlead` `14| c, causing the previously :operated speech cut-in relay 81litorelease, andV is confnected i :through the right make contact 'of relay 914211, rightnormalcontact of relay 148a, over lead 1I2c1a`nd path previously. 'preparedjby thel selection relays to speech :Lutein relay l8,52 which .'operates.; `The operation ofrelay'fv852 coincides wwithwthat point inl the revolution of *drum* 82| -between two of `the threev recordsthereon.` The word eleven" is, therefore, electrically `trans-- `mitted to the network of announcement trunks viously extended ,to its righti armature" breaks duringl the furtherrotation `oifllm drum 82|. I

When relay 14211 operates following theyopenin'g of lead 862 at cam 86|, it` transfers Athrough' its left outer transfer circuit the furtherA advance of the 1,40 relay grcupjofeountingrelays from` controlof cam 86|{to cam 858.,` h n When foam 858jnext grounds lead 858e. circuit path `is completed to batteryrthrough left? outerltmake `contact of relay 14,211, 4right inner makelcontact of relay 802, left, make contact of l `relay 1Mb, left 'inner make contact of relayx1l2b., and winding of relay 143a,\1ead 808 to battery.` Relay 143a operates, prepares the usual locking circuit at its left make contact and transfers its right armature from lead 142eto lead 148c causing'speech cut-inurelay 952to release and the` pre-selected speech cut-in relay 936 lIto operate.

VWhen `cam 858 removes groundfromllead 859, Vrelay `1431 operates and transfers the `control `lead to the succeeding pair of` relays] r f In this manner each of the; other pre-selected speech cut-in Vrelays 84,5, 81,4, {4h-and 828 isY operated in theorder indicated,each` `remaining operated during the rotation .of the respective film drums through one-thirdof a revolution.

relay .929, when cam 858:next grounds and opens Following the-operation ofl relay pair 141 and i 148a. operating releases relay 929 by transferring theA ground connected to its right armature from Time signal and release When relay 8 operatesl at the end of a 15- second period, asalready explained, it grounds lead ||8`at its right outer alternate make contact. Ground on lead ||8 through left outer normal control of transfer relay |68, lead |12, left inner 'make contact of relay 80| to battery through winding of relay 804 which operates, in turn operating relays 805, 828 and 808 over obvious circuit paths. The purpose of relay 805 will be explained later; Relay 808 operated prepares a pathywhich` includes the winding of relay 801, Relay 808 also opens the operating path of relay 80| but the latter is now held by the vground at the left makecontact of relay 804.

Relay 828`operated connects the output of repeating vcoil 820 to the input of amplifier 812. The input of repeating coil 828 is connected to a suitable source of tone, such as a tone alternator 83| with adjustable volume control 830. This tone is heard by the subscriber and constitutes the time signal. i

When relay ||6 releases one-half second :after operating the operating path of relay 804 is vopened and, it releases, in turn releasing relays 80|, 828, 805 and 808. Relay 808 isslow in releasing, hence, relay 801 operates from ground at the right normal contact of relay 804 and remains operated until relay 808 opens its left make contact. When relay 801 operates, it removes the battery from lead 809 causing the release of relay pairs in relay group 140. When relay 808 finally releases relay 801 also releases leaving the system prepared for the next announcement. y

In the event relay group 140 Iailsto progress under the control of the cams in the manner described, relay 80| Vwill be normal when ground appears on lead |12. In this case the ground on lead |12will be connected through the inner normal contact of relay 80| tothe right Winding of relay 806 to battery. Relay 806 will operate and lock over an obvious circuit path. Relay 806 operated closes a circuit path for'operating relay 8|3 which functions as will be described later, to transfer the service to the other time announcing machine. i l `Pronouncements involving less than seven film records In the example given the announcement following the introductory phrase, viz., eleven.

lforty-five and three-quarters involved the output of six iilm drums obtained by successively grounding leads 142e, 143C, 144c,|45c, 146e and 141e. When the quarter minute announcements and one quarter, leand one ha and three-quarters are not required the corresponding control leads 145e, 146o and 141e are made ineffective. Thisis the case during the last 15- second period in each minutes when counting relay pair 204 and the correspondingselection relay '504 are operated.

lead 859, relay pair 148 is left operated. Relay Relay 504, operated, disconnects, at its left normal contact, lead 145e from lead 850s and, therefore, from the winding of speech cut-in relay 814. It also closes a circuit path from ground at its right middle armature Vto battery through relay 135 which operates. Relay 135 in turn closes 0bvlous circuit paths for operating relay pairs 146,

141 and 148. The a relays of these pairs through their right armatures extend the right make contact of relay 145a directly to lead 148e. The b" relays make the advance circuit path ineffective beyond relay pair 145. The b relays also transfer their portion of the chain circuit path from' their rightnormal to their right make contact.

Under these conditions when check relays 152 to 158 inclusive, are caused to operate in the manner previously described, only relays 152 to 155, inclusive, will remain locked up. Relays 156, 151 and 158 will release and close their portion of thechain circuit through their left normal contacts. This is the condition prior to announcements such as: Y

"Eleven forty-six Twelve oh clock.

One oh nine Ten thirteen For announcements such as:

Three ten Four twelve Five oh and one half only one nlm drum is requiredto announce the minutes. In this case relay pair 145 is operated, and lead 144e is not connected to any speechcutin relay. Hence, check relay155 should be normal to effect the closure of the chain circuit previously referred to. The paths for operating relay pair 145-,are three in number. (l) Ground at right outer make contact of relay 4|0 (which is operated for one minute beginning 9'45, 19'45", 29'45", 39'45", 49'45" and 59'45", past the hour), through the right outer normal contact of relay |6 (which is normal from 9'45" to 59'45" pasty the hour), windings of relays 145-by and 145a to battery on lead 809. (2) Ground at right outer make contact of relay 4|0 as before,'right outer make contact of vrelay 5|6 (which is operated for ten minutes beginning 5945 past the hour), right normal contact of relay 504 (which is normal duringthe first 45 seconds in each minute) through winding of relayl pair 145 to battery. (3) Ground at right outer make contact of relay 5|| Synchronization of driving motor iaith clock Means are provided for synchronizing the driving motor 85| with time in order that the announcement will start at approximately the same number of seconds prior to the time signal in each l5-second interval. Associated with the driving motor is the usual governor and means well known in the art for maintaining approximately constant speed, usually within a Iew per cent of the desired speed. In addition, the ar rangement about to be described checksv the po- .(which is operated for ten minutes beginning i will again operate and release leaving relay |44 operated for another revolution of shaft 851. If,

sition of the lm drums once everyfthree secondn speeding iup* or slowingfxdownftheldriying moto depending, on Whether:.thefashait g is n behind or.- ahead of the position necessary to maintain :syn:

chronization'.

ground lead |641` Leads '|64 and |65extend re- .c f

spectively,' through the right innerwandright middle normal contacts of; transfer relay |68., connecting;l respectively, withi leads, I 8 I and |62,

windings of relays I4| and |42 toA battery. Since the a relayof a countingrelay pair remains operatedf'for 11/2 seconds, `and the next higher` i numberedarelay operateswone second .later i there is fa l/z-second period in (whichtwo succes'-` sive ai relays. are operated;` 'fhereforerina. given three-second period, relaysV |4| and.|42.are

bothoperated for 1/2 second, in the following second only relayn|42 isloperated, in the ,nextel/2 second neither relayis operated and in` the last one second of the three-secondyperiod, relay `I4 I alone'fis-operated. y

- Lead uns whichterminates eine lftfarratre of relays `|4| andwIII is'grlmdedionsay, 1/4

second;` once during each` revolution ofearnBGI.`

`Synchronization is :maintained i so .long as this ground pulse occurswhollyrwithin the, 1/2 second leftwinding of relay |44 which operates ,and

locks through its right winding and right innerA make contact to groundA a@ the y.normal contact of relayy |45. The right outer'make contact of relay |44 `closes a circuit notshown but well known in the art, toeffect a reduction in the speed of the motor. The left innerfmake contact of relay |44 extends lead |46 i ,to-battery 1 through the` middle winding of` reIayJ'II-Kwhich operates and locks.`

through its left winding and make contact to ground on lead |46. The purposeof relay III is to prevent the premature operationof relay |45 in the event relay |42 releases before `carrrk86|jre'-` vmoves 4the i ground :from lead |46." It thus as- 4 s'ures a decrease in the speed of therritorenf` during `for a fully revolution of shaft i 851.` Folf lowing the opening of thecontact at cam 86| rer: lay |1| releases but relay'l44 remainslocked.

Ifrelayq|42 is-again in its operatedfposition when cam 86| `next grounds lead` |46,'.relay` I 1| however, the reduction in speed eilected AbyY relay `|44 is such `thatuthe, groundron lead|46occurs when `both relays |42 and `|4|arenormal,'relay |45 `operates over apath`which'inc1udes the normal contacts of relays |4|, |42 and I1 I, thereby causing the release of` relay |44 whichagain places thev motor speed `under control of the governor already referred to. e l Conversely, when the speed of thedriving motor is below that requiredto maintainsynchro- `nization,cam` 86| will eventually ground lead |46 after relay I4| has operated. This .causesrelay |43 to operate `in turn operatin-grelay 4 I] |.'1Re

Y Y. e 2,004,248

j tionof relay] A i j i locks to the normal contact o! relay I4- and closesa circuit, mort( shown) through its left c' rc ff asrlmzr.

chcckcfezoe 'puls `ela r startkey |54 anob the right Vinner 4c I relay |24a. .Wheng operates` time, relay Y24a` rele leases the secondlti f 1ers .cheek di# rectly the periodic 4'pc-:rat land"` releaseoffre- 35 `lays |24a and |2412` an` herefore',indirectly` the periodic make 14anctlfi calmiV 4pendulurnjcjontact. The iirst chainc'onsis firelays |26,^|2I and |28. Relay |26 is energized wheneverjrelay lay I 29,thevr`st relay ndfirifeatzhA fone-'second `peeleasirig` time of eachslow greater than JA; second ..50 ljjeach' chain', via., 'relays u |28 and I3] .will y ease' unless some trouble` e breaks thechaiJ lperiodic events initiated by `the pendulumfnfthisrj caser"elay |28 or` |3|` e `would release" an losean obvious path/for o`p`` 55 erating relay |34 whose function will be explained later. l

u e .Relay pair .|24wp`erforms another function, viz.,`

. to `checkthe op'eationfand release of odd-` wand even-numbered pairs ofv counting relays inrelay 60 groupfl. This is accomplished Withthe ald of; relaysf|32 and`ll33., Wheneverrelay |22?) releases yto `cause a b relayv Vof` an' oddnumbeed pair of counting relaysjtooperate, it also `'causes relay` l|24b to operate Whenever 're1ay"|22b" releases65 lto cause a fb e y] of 11an even-niimbered -pair` of counting relaysltooperate, italso causes re-` layj`|24b`to release e An alternate'circuit path is, e therefore, maintained to 'l'iolll relay' |33 operated; first,` from ground at 'fthe make` contact-of .70d

an oddfnumbered f bf relaythrough"rightfinner makelcontact of relay |24;" secondjfromground t at the vmake contact "ffan"Aueveerr-f-r'ifu'xnbered` eb relay through the right outer Lnoi'm'al contact of relay |2411. In.; a similar.;mannerfnrelay "|32 'I5 eiay chain, is energized e c y 8 checks the release of the operated counting relay pair, first through the right outer make contact of relay |24b to make contacts of even-numbered b relays; second, through the right innernormal contact of relay |24b to make contacts of odd-numbered b relays. slow in releasing and relay |32 is slightly slow in operating in order to prevent their functioning falsely during the instant their paths are switched. `Should relay |33 release or relay |32 operate, an obvious circuit path is closed for operating relay |34, whose function will be explained later. y

rIt is necessary to release and restart relay pair |24 at the beginning of each l5second interval in order to maintain the proper checking relations. When relays ||a and ||6 operate at the begin- Vning of each l5second period, the latter causes clock circuit corresponding to relayY 3|4.

relay ||1 to operate and relay pair |24 to release. Relay |33 is now held through the right outer normal contact of relay |2412, right outer make contact of relay ||1 to ground at right make contacts of relay ||5b.

When relay ||6 releases one-half second later, it recloses the battery feed to the left winding of relay |24b and connects ground through its left outer normal contact, left make contact of relay H1 and previously traced path for operating relay |24a. Relay ||1 is slow in releasing so that although its operating path is opened. at relay H6 it remains operated long enough to permit relay |24a toY operate. When relay ||1 does release, relay |24b operates in series with relay |240.. Relay |33 is now held through the right inner make contact of relay |24b and right inner normal contact to ground at left make contact of relay |0|b.

Transfer of eitherY machine to clock reays of other set When relay |34 is caused to operate `(in the manner already described) because of failure of the clock or its associated counting relay group |00, it locks through its right winding and right inner contact to ground at locking key |31.

Relay |34, operated, completes a circuit through its left inner make contact, locking key |381 normal, ringer |38 and ringing machine |40. Ringer |38 sounds an audible alarm. An obvious circuit path is closed for flashing lamp |36 under control of interruptor |35. Ground at left outer make contact of relay |34, left inner normal contact of locking key |31, r,normal contact of locking key to battery through transfer relay |68 which operates in turn operating multi contact transfer relay 3|4 over lead |69. I

Transfer relay |68, operated, also transfersr leads |12, |13, |14, |8| and |82 from contact with leads ||8, |62, |63, |64 and |65 to contact with leads |15, |16, |11,|18 and |19, respectively. The last-mentioned group of five leadsis designated 4|3 and terminates at the respective break contacts on the relay in the other clock-operated control circuit corresponding to' relay |68. Transfer relay 3|4, operated, transfers the leads of the selection relays to the group of leads designated 6|3 (Fig. 6) which terminates at the respective break contacts ofthe relay in the other In substance lead groups 4|3 and 6|3 of each clock-operated control circuit connect with lead groups |66 and 3|5,resp'ectively, of the other clock-operated control circuit.

It follows that when transfer relays |68 and 3|4 are operated the control of the associated Relay |33 is slightly announcement machine and selection relays is transferred to the counting relays of the other clock circuit. This transfer may be effected manually by the operation of locking key |31 in which case lamp '|36 lights dimly when relay |34 is normal or flashes dimly when thisrelay is operated. Locking key |80 permits the cancellation of the automatic transfer feature.-

Checking the output of amplifiers therefore, checks the circuit continuity between the output of repeater 812 and the'light source of the films. Y l

Following the time signal and prior to the beginning of the next pronouncement, relay 8|0 should be normal. Should a speech cut-in relay remain locked up or crossed with ground the associated film record will be transmitted to amplifier 812 causing relay 8| 0 to operate. During this time cam 858 momentarily grounds lead 860 completing a circuit path through the left normal contact of relay 80|,V right normal contact of relay 801, left winding of relay 806, left normal contact of relay 14m, ,to battery through make contact of relay 8|0. Relay 806, therefore, operates and locks over an obvious circuit path to ground at relay 808.

During the periodin which the pronouncement takes place relay 8|0 operates and releases as the lm records pass the light source. Relay 8|0 is ssucienltly slow inv releasing to vremain operated between successive words of the introductory phrase on nlm drum 866 but may not remain operated between successive records on the small lm drums. It should, however, be operated by the time cam 858 grounds lead 860 momentarily to ascertain if relay 8|0 is operated. If it is not operated the following circuit path is closed to cause relay 806 to operate: ground on lead 860, left normal contact of relay 80|, right normal contact of relay 801, left winding of relay 806, left outer make contact of relay 14|a, normal contact of relay 8|0 to battery. Relay 806 operates in this circuit and locks through its right winding to ground at relay 808.

A check is also made to'assure the proper transmission of the time signal tone Ywhen relay 828 operates. Following the release of the last operated speech cut-in relay required by the pronouncement it was vshown that relay 80| was caused to operate. This relay opens, at its left normal contact, the connection with lead 860 thus preventing relay 806 from being falsely operated should lead 860 be grounded before the time signal is impressed on amplifier '812. When relay 800 operates, causing relay 628 to operate, slow operate relay 805 is also operated and connects ground over the previously traced path to the left winding of relay 806. However, if the tone is impressed on amplifier 812, relay 8|0 will operate to remove the battery from the left winding of relay 806 before'slow operate relay 805 completes its portion of the circuit path. If the tone, due to trouble conditions, is not'applied, relay 8|0 fails to operate and relay 805- is permitted to cause relay 806 to be operated.

Whenever relay 806 operates, it cIoses an ob'- vious circuit path for operating relay 8|3 which machine. w

wie?

' l twoclock-operated control circuits and associated machines in, operations.butonly` `one providing the service, arrangements areprovided whereby each clock acts asta checken the other; w Acontnuous check is madeto assure that, the

Voperatedselection relays` in each of the two clock circuitscorrespond one tothe other; This is u accomplished by acircuit -pathtwhichlincludes make contacts onetheselection relays in `both clock-operated control circuits.` As an aid in tracthrough make contactsxof operated selection re-` lays 'in groups 5|0, 500, and |00 `ofboth circuits, lead 103, winding of relay 104 to battery. Relays l 102 and 104,' therefore, remain operated, Should 11 the circuit path-be crossed with ground or battery orbecome open, feitherorlboth relaysawill release and open an obvious circuit path which holds relay 109` operated; Should relay 109:be caused to release, further announcementsfpare` cancelled in the manner to be describedlater. 'I' Should the` S15-second cycle asmeasured by relaygroup |in each of the two clockeoperf ated control circuitsvbe out of phase bylaprecle-` termined amount', relay `109 will-becaused to re-` lease. j Assume the two clock-'operated control r circuits are out ofphase byvonesecond-,and that grounds .lead |61 `for the` purpose of operating thefirst circuit is leading. `When relay IIBfin thelrst circuit operates, markinglthe end of a 15-second period, it closesba `circuit path over lead '|59' to battery through winding of` relay 1081which operates connecting its windingto lead |10'. lead |10 is lcross-connectible to Vthe `right armature or-normal contact of relays |02a` I03a or IOIa, depending on thel desired degree of syn,-

chronization between the two clockfoperated conl trolcircuital Assumelead |10 is connected tothe right. normal contact [of` relay l |02a." `where it .is` I extendedrtoground at the left'normal contact Relay 109, operated`,l closes through.- itsriglitV make contactanv alternate :holding path for .relay r109 over lead |83`to ground Vaiz'thevleft outer normal contact ofrrelay |60.`

When relay I I0A releases. one-half` secondafter f operating, it advances. the countin one or more voi!` counting relaygroups'200, 2| 0, 230 and 300,j in

the manner previously described. .'These, in turn,

.change'thesetting in one or moreoi the selection relaygroups 500; 400,` 5|0` and 600, thus open- 2 I I n6 in `the `secondV clock-operated control circuitv operates` one second after relayIIBV inthe iirst clock circuit. Relay 1|6- and leads-1|5, IIT and 41I9, shown `at A on I5'ig.'1,` are associated with of the ftwoj black? the secondcloclrfoperated .control circuitfinfthe identical way inwhich 4relay 1Il9y and leadsl |59,-

I03, and |1I|n are shown associated `withthe Ailrst clockfoperated control circuits;` Relay.1|6, thereforca operates, lockslto the associated |02a relay inthe .second clock circuitoverlead 1|8, and connects` ground tothewinding of relay 109..,

after relay109releases and before relay 1|9 opcrates.`

aswaslmadej" the first circuit. The previously traced circuit pathior operatingzrelays 102 and 'subsequently releases t following the, operation of relay I02a in the secondclock circuit.` I t Y yIt will be, seen that whenleads `and 1|8 are connected to the normal contacts 'of their respective `|02a relays, the. two clocks may-notlag by` an amount greater than one second plus the releasing` time ,of relay 109 otherwise relay 109 l.

will close its normal contact.v By4 connecting leads When` relay", IIB in the second clockefoperated f control circuit releases, the same. change 'i'fthe setting of` `thcassociated selection relays ismade.

`104` is', therefore, reclosed, and theserelaysopi `erate, ;reclosing `the, circuitpath for holding reV lay 109 operated, independent ofrelay 1I6, which |10 and 1I9 "to other pointsinthe7respective |00 relay groups, the allowablelag maybe .in-30 'any desiredl value., By not connecting'these leads` creased ordecreased inone-hali second steps to ,to any point, the allowable lag between the clocks becomes one-half second plus they releasing timey i A `oigrelay 109. c, 5 w l :When either clockmlagsor. :leadsthe other by" A,a s uicient amount, permitting relay 109 ,tov re# lease, relay -1|| is causedto operate overanyobfat` locking key 1| 0, causes lamp 1| 2 to'lightand ringer |39, which sounds an audible alarm.

Relay, 1| I,l operated, t also `removes the ground extended `through the normal contacts ,of- ,lock

ing key4 Nitot-leads 1| 9 :,andg120grthus releasing relay ,BIB or 8I9, depending on which clock- "operated controlcircuit is providingv the time l service,"which cuts oir all iurther time pronouncef,`

ments. n

is caused to release.

. Tf'antefof sacicefrom either machine 'i WWPWW" vided whereby` certain trouble conditionsfwill ment trunks to the emergency 1 machine.

x Referring` tota in Fig. s, with `100mm; keysz `operated (as shown), a circuit `path is closed for` operating relaytl.Y Ground atlright normal `contact of relay1'|,|right normal contact oi' key 1M,` lead 1I9,right make contact oil-,key 0I2,right normal 4contact of relay 8I3 to battery through` windingot relay 818.V Relay19|8,lo`per ,m

ated, connects` the output of `the rst `machine to the announcement trunk and places` relay 825 l un-` Either machine finayprovide. he lume ,nommem?"Slimme-fthe other then acting-as,` theemersenrmachine. Arrangements eremo-.1 `(Hause anlautomatic` transferer` theannounce-f` der control or the ilrst clock-operated control cirv c When ttvfo,-,Vuzayf,4 locking keytll `is operated to close lower lett make contact as shown; a

Yobvious p ath for operating relay 8|3. Marginal relay 832 does not operate in series with a single speech cut-in relay but should two such relays be caused to operate simultaneously because of 'a cross in their operating leads the increased flow of current in the winding `of relay 832 will operate it.`

' When relay 8|,3 operates, it locks through its left winding and left inner make contact to ground at key 8l2. It also lights lamp 8H over an obvious path and connects ground to lead |61 causing ringer |39 to sound an audible alarm.

Y It opens circuit path of relay 8|B and closes a circuit path through its right make contact, left contact of key 8M, left normal contact of relay 8Il to battery throughwinding of relay 8l9. Relay 818 releasesV and relay 8l9 operates, thus effecting the'transfer of service.

What is claimed is:

1. A system of relays including a plurality of relays adapted` to be set in correspondence to elements of time, a source of isochronous pulses, connections from said source to said relays to progressively operatey the relays, whereby' the setting of the relays will periodically correspond to the time of day, a second system of relays similar in character to said rst system of relays, and means for electrically comparing the settings of the rst system with those of the second system. v

2. `A system of relays including a. plurality of relays adapted to be set in correspondence to elements of time, a'source of isochronous pulses, connections from said source to said relays to progressively operate the relays so that the settingY of the relays will periodically correspond to the time of` day, a secondv system of relays simi- Vlar in character to said first system of relays,

lays adapted tobeset in correspondence to hours,

a second group adapted to be set n correspondvto progressively operate relays of the rst group so that the setting of relays in the three groups will periodically correspond to the time of day,

aV second system of relays similar` in character to said rst system of relays, means for electrically comparing the settings of the first system Y with those ofthe second system, and means for indicating discrepancies of predetermined magnitude between the two systems of relays. '4. A system of relays including a 'source of isochronous pulses, means for integrating said pulses into fractional parts of a minute, a minute, a ten-minute, an hour, andtwelve-hour periods vof time, means cumulatively registering .such periods of time, checking means responsive tothe interruptions of the normal isochronous pulses and also responsive to the failure in the integration of said pulsesinto fractional minute periods, and means for indicating the operation of -the checking means.V y 5. A system of relays including a plurality of relays adapted to be set in correspondence to elements of time, a source of isochronous pulses, connections from said source to said relays to progressively operate the relays so `that the setting of the relays will periodically correspond to the time of day, aisecond systemV of relays similar in character to the first system of relays, means for electrically .comparing the settings of the first system with those of the second system, checking means responsive to interruptions of the normal isochronous pulses and also responsive to the failure of Vsaid relaysV to progressively operate, and means for indicating the operation of the checkingmeans.

6. A system for announcing the time of dayV in the form of speech comprising a plurality of isochronous pulses, means for integrating said pulses into uniform successive periods of time,

Vmeans for registering said periods of time, means controlled byV said registering means for periodically preselecting a combination of said cells, means for associating the output of each cell in `said combination of Ycells with said sound reproducing device to make an announcement of the time of day'prior to the precise instant of time Vto, which the announcement refers, an audible signal, andmeans for associating said audible signal .with said'sound reproducing device to indicate the precise instant of time'to'which the announcement refers. Y A

7; In a system for periodically` announcing the Vtime of day, thecombination of a source for generating isochronous pulses, means for integrating said pulses into fractionalrparts of a minute, a minute, a tenlminute, .an hour and twelve hour periods of time; means for cumuklatively registering such periods of timefa time announcing machine including a series of speech records each having individual inscriptions thereon, such as an introductory phrase, words and syllabic parts of words, and means responsive to registration of said periods of time to periodically preselect a particular combination of Y speech records and predetermine the order in which` the individual speech records of said combination shall be used.V

8. In a telephone system for periodically announcing the time 'of day, a trunk network, subscribers lines, means for connecting said lines to the network, a source for generating isochronous pulses, mea-ns for integrating said pulses into fractional parts of Va minute, a minute, a ten minute, an hour and twelve hour periods of time, means for cumulatively registering such periods of time, a time announcing machine including a series of speech'records having out'- 

